We examined the mechanism by which Antarctic krill, Euphausia superba, shrink, and suggest that cellular changes occurring during shrinkage may provide a means for identifying krill that have undergone shrinkage. We compared the muscle tissue of juvenile, adult and shrunken adult krill to identify changes in cell number associated with maturity and shrinkage. Comparison of the absolute number and density of nuclei in abdominal segments of juvenile, adult and shrunken adult krill revealed differences related to maturity and shrinkage. Shrunken adult krill had nearly twice as many nuclei per unit area than adult krill that had not shrunk. This suggests that krill shrink by a reduction in cell volume, rather than cell loss. This simply detected variation in muscle cell nucleus density may be useful in distinguishing shrunken adult krill from juveniles, and contribute to our knowledge of age structure in natural populations.

Item Type:	Refereed Article
Research Division:	Biological Sciences
Research Group:	Ecology
Research Field:	Marine and estuarine ecology (incl. marine ichthyology)
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the environmental sciences
UTAS Author:	McGaffin, AF (Ms Angela McGaffin)
UTAS Author:	Ritz, DA (Associate Professor David Ritz)
ID Code:	21923
Year Published:	2002
Web of Science® Times Cited:	8
Deposited By:	Zoology
Deposited On:	2002-08-01
Last Modified:	2011-08-01
Downloads:	0